Discover in-depth answers to 99 essential questions in Environmental Science and Disaster Management. Tailored for diploma and degree students worldwide, our blog offers clear, detailed explanations on topics ranging from sustainability to risk mitigation. Whether you're studying for exams or expanding your knowledge, you'll find reliable, concise insights here.
Sunday, 22 September 2024
99 essential questions in Environmental Science and Disaster Management
2. Difference between renewable
functions of the forests-Productive
8. Hydrological cycle
18. Reasons for global food crisis
22. Causes/effects of land degradation
24. Solar Energy
29. Types of ecosystem
35. Food web
43. Structure of grass land ecosystem
47.Over exploitation of natural resource
58. Causes of water pollution
64. Effects of noise pollution
69. Causes/sources of thermal pollution
71. Causes of radio active pollution
75. Solid waste management
79. Hazard
84. Environmental Stress
93. Bhopal tragedy
Types of Disasters
Module-4-Disaster Management
91. Land Slide
The movement of a mass of rock, debris, sand or earth down to a slope is called land slide. Land slides are caused by either natural or man made reasons. Man made reasons are:
1. Deforestation
2. Blasting and mining
3. Earth work
4. Agriculture or forestry activities ( logging )
5. Urbanization which change the amount of water infiltrating the soil
2. Blasting and mining
3. Earth work
4. Agriculture or forestry activities ( logging )
5. Urbanization which change the amount of water infiltrating the soil
92. T- Sunami
T-sunami is a series of waves in a water body caused by the displacement of a large volume of water generally in a large lake or ocean. Earth quakes, volcanic eruptions and other under water explosions including detonation, land slides, glacier calving, meteorite impact and other disturbances above or below water, all have the potential to generate t-sunami. The name t-sunami is a Japanese oigin, meaning as 'Harbour wave'. Identified t-sunami prone areas are Indonesia and Japan.
In Japan earth quake engineering measures have been taken to reduce the damages caused on shore. The country has built many t-sunami walls of up to 12 meters high to protect populated coastal areas. Other localities have built flood gates of upto 15.5 meters high and water canals to redirect the water from an incoming t-sunami.
Effects of T-sunami
- Loss of lives
- Loss of properties
- Loss of live stocks
- Negative impact on the economy of the affected region.
- negative impact on tourism.
- Alteration of the sea side terrain
- Wild life causalities
- The sea will be temporarily littered with debris
- Coral or marine reef damage
- Loss of properties
- Loss of live stocks
- Negative impact on the economy of the affected region.
- negative impact on tourism.
- Alteration of the sea side terrain
- Wild life causalities
- The sea will be temporarily littered with debris
- Coral or marine reef damage
93. Bhopal tragedy
Bhopal Gas Tragedy was a chemical disaster happened in an Indian place Bhopal located in Madhyapradesh state. 45 tonnes of Methyl Isocyanate gas along with traces of phosgene leaked from three storage tanks of the union carbide industry exposing several thousands of people. This gas was used in the production of pesticides.
According to an official estimate there are around 6 lakhs gas victims in 36 wards of Bhopal. The causalities reported were:
- 12000 death of people
- Physically challenged new born babies
- Pre mature deaths
- Deformities among the children including congenital heart ailments, holes in arms and impaired eye sights
94. Chernobyl disaster
Chernobyl Disaster was a nuclear disaster happened at a place of Chernobyl in former USSR. Series of nuclear explosion accidents occurred in nuclear reactor and blew large amount of radio nuclides high into the atmosphere. The accident killed more than 30 people immediately and as a result of high radiation into the surrounding areas of 35 km radius, nearly 1,35000 people had to be evacuated. The casualties reported were:
- Several deaths
- Over 400million people were exposed to the radiation.
- Several diseases like ulcerate skin, nausea, loss of hair, bone cancer, thyroid cancer etc. were reported.
- Several agricultural fields, trees, shrubs, plants etc. affected with radiation.
- Economical impact to the country. Other countries stopped import of food materials from USSR in fright of radiation effect.
- Over 400million people were exposed to the radiation.
- Several diseases like ulcerate skin, nausea, loss of hair, bone cancer, thyroid cancer etc. were reported.
- Several agricultural fields, trees, shrubs, plants etc. affected with radiation.
- Economical impact to the country. Other countries stopped import of food materials from USSR in fright of radiation effect.
95. Earth quake
Earthquakes or tremors are produced by the passage of vibratory waves through the rocks of the earth.
As precautionary measures, the people on the earthquake zone will be educated about the precautions to be taken.
Buildings and houses will be permitted in accordance to the guide lines from the engineering departments.
At the ongoing stages of the earthquakes, the people will be instructed to stand out in safe open places.
After the incident, the priority will be given to search and rescue operations to save the people from the collapsed buildings.
Relief camps and rehabilitation will be done in the next stages.
96. Nuclear explosion
A nuclear explosion disaster occur as a result of rapid release of energy from nuclear reactors. Nuclear explosion produce radiations and radio active debris.
Causes
1. Military operations ( i.e. nuclear weapons ).
2. Nuclear test and experiments.
3. Nuclear accidents in nuclear power plants.
2. Nuclear test and experiments.
3. Nuclear accidents in nuclear power plants.
Effects of nuclear explosions
- Immediate death of people and animals.
- Long lasting impact of nuclear radiation around the explosion sites
- Premature deaths.
- Genetic mutation.
- Poisoning of food.
- Chronic health affects like skin cancer, bone necrosis, thyroid cancer etc.
- Affect plants and animals.
- Release of huge temperature and radiation affect the aquatic life also.
- Long lasting impact of nuclear radiation around the explosion sites
- Premature deaths.
- Genetic mutation.
- Poisoning of food.
- Chronic health affects like skin cancer, bone necrosis, thyroid cancer etc.
- Affect plants and animals.
- Release of huge temperature and radiation affect the aquatic life also.
97. GIS, GPS & RS
GIS, GPS and RS are the new emerging technologies used in various stages of disaster management.
GIS (Geographic Information System)
GPS (Global Positioning System)
RS (Remote Sensing)
GPS (Global Positioning System)
RS (Remote Sensing)
These application tools are useful in disaster management decision making. The evolution of computer technology and the availability of hardware is helpful for the rapid expansion of GIS in both disaster research and practice.
GIS is useful for hazard zone mapping and during emergency conditions. Mitigation of people are easily possible by using these maps.
GIS and RS are much beneficial in mitigation strategies and preparedness plans.
Realtime geographic data can improve the allocation of resources for response.
GIS and RS are much beneficial in mitigation strategies and preparedness plans.
Realtime geographic data can improve the allocation of resources for response.
98. Energy Resources
The earth is the store house of energy. The fossil fuels beneath its surface, the wind and water flow above its surface, the plants growing on its surface, the sunlight falling upon it, are the sources of energies on the earth. Types of energy resources are renewable and non-renewable energy resources.
Non-renewable energy resources
They are available in limited amount and are developed over a long period of time. Because of their indiscriminate use they are likely to be exhausted in the near future. Examples are: Fossil fuels, Coal, natural gas, and Nuclear power.
Renewable energy resources
Renewable energy resource is the natural energy flow and thus it has the potential of being continually replenished. So it can be used infinitely. Examples are: firewood, animal dung, solar energy, wind energy geothermal energy, tidal energy, hydral energy etc.
Fossil fuel
Examples for fossil fuels are coal, petroleum and natural gas. Fossil fuels are the remains of organisms that lived 200 to 500 million years ago. They are formed inside the earth crust through heat and compression of organic matter buried underneath.
Coal
Types of coal based on its composition are anthracite, bituminous and lignite. Coal is used for cooking, industrial heating and for production of electricity in thermal power plants. About the 5 percentage of world’s coaI reserve is found in India. Jharkhand, Odisha, West Bengal, Madhya Pradesh, Andhra Pradesh and Maharashtra are the coal states of India. India has a huge coal deposits left for nearly 200 years. Coal mining is very harmful to the environment. It causes air pollution, respiratory diseases and lot of other environmental issues.
Petroleum
Petrol, diesel, kerosene etc. are the petroleum product. Whatever oil we are getting from the oil reservoir is the crude oil and after distillation process, we can separate Petrol, Diesel and kerosene.
Natural gas
Natural gas is a mixture of methane, ethane, propane and butane. It is available as LPG and CNG.LPG consist of propane and butane. It is low cost and low pollution.
99. Explain the Importance of renewable energy
Renewable energy resources are inexhaustible. This is available on earth abundantly. Examples are solar, wind, tide, geothermal and biomass. The importance of renewable energy resources can be listed as:
1. Reduce fossil fuel consumption so that it can be made available to the future generation also.
2. Reduce environmental pollution.
3. Economical than fossil fuels.
4. Reducing the use of fossil fuels and promoting the renewable energy can help the governments to depend on other countries for oil.
Terminology of Disaster And Management
Module-4-Disaster Management
83. Sources of chemical disaster
Sources of chemical disasters are:
1. Transportation accidents while moving the chemicals by rail, road, ship, air etc.
2. Leaking of pipe line carrying toxic gases.
3. Explosions or leakage in chemical factories.
4. Oil well fires.
Bhopal gas tragedy was one of the major chemical accident happened in India.
Minamita tragedy was a chemical disaster occurred in Japan.
84. Environmental Stress
It is pressure on the environment caused by natural hazards like earth quake, flood and draught or by human activities like generation of pollution.
Study and analysis of environmental stress helps to reduce its effects and response after disaster.
85. Disaster Management
Disaster management can be defined as the organizing and managing of resources and responsibilities for all the activities related to the disasters.
The various activities involved in the disaster management are:
1. Prevention of hazards that lead to disasters
2. Reduce the risk and severity of any disaster.
3. Capacity building of vulnerable community.
4. Preparedness to deal with any disaster.
5. Prompt response at disaster situations.
6. Assessment of the severity and effects of disasters.
7. Evacuation, rescue and relief operations.
8. Rehabilitation and reconstruction.
The various activities involved in the disaster management are:
1. Prevention of hazards that lead to disasters
2. Reduce the risk and severity of any disaster.
3. Capacity building of vulnerable community.
4. Preparedness to deal with any disaster.
5. Prompt response at disaster situations.
6. Assessment of the severity and effects of disasters.
7. Evacuation, rescue and relief operations.
8. Rehabilitation and reconstruction.
86. Stages of disaster management
Disaster management include mainly of three stages:
1. Pre-disaster stage (preparedness)
2. Emergency stage
3. Post disaster stage
2. Emergency stage
3. Post disaster stage
Pre disaster stage (Preparedness)
It is the activities that enable all the communities to deal with any disaster. The activities involved in disaster management stage are:
- Training and emergency exercises for community emergency response team.
- Develop emergency warning system, evacuation plans and emergency shelters.
- Ready health systems, food supply and other supplies and equipment for emergency response stage.
- Training and emergency exercises for community emergency response team.
- Develop emergency warning system, evacuation plans and emergency shelters.
- Ready health systems, food supply and other supplies and equipment for emergency response stage.
Emergency Stage(response)
Response stage start when any hazard event occurs. It basically concentrate at first to provide immediate relief to the affected community in terms of food, water and shelter. The response activities include public warning system, emergency operations like search and rescue, building temporary shelters and providing all immediate needs of the affected community.
Post disaster stage ( Recovery )
The recovery stage start after the immediate threat to the human life has subsided. It involve the long term activities that help the affected community to stand back on their foot and in a better position to deal with future disasters. These activities include rebuilding, insurance claim processes, various grants and aids that are provided for community for recovery and come back into normal life in addition to medical care facility.
87. Mitigation
Mitigation is the measures taken prior to the impact of hazard event to minimize the effects. Mitigation measures are taken in two stages. At first stage, try to prevent or reduce the intensity of the occurrence of the particular hazard. And at the second stage, try to reduce the impacts of the particular hazard by reducing the vulnerability of the community or by enhancing the capacity level. The mitigation level involve the following activities:
1. Legal frame work
2. Land use planning
3. Grants, subsidies, insurance, incentives etc.
4. Training and education.
5. Mitigation plans on construction sites and building.
88. Hazard zone mapping
It is the mapping of the areas that are affected by or vulnerable to the particular hazard. They are typically created for natural hazards such as earth quakes, volcanoes, land slides, flood and hurricane.
- It is a part of mitigation measures.
- It helps to mitigate the after effects of the hazard.
- It help the community to aware about the potential threat.
- It help the authority to carry out disaster management plans easily.
- It helps to mitigate the after effects of the hazard.
- It help the community to aware about the potential threat.
- It help the authority to carry out disaster management plans easily.
89. Land use zone mapping
Land use zoning is a part of mitigation measures taken by government to reduce disaster effects. Governments restrict the use of areas of lands that are zoned for a particular purpose.
While there is no universal coding for land use zones, there are many types of land use zones such as residential, agricultural, industrial, historical etc.
90. Heat Island
Temperature levels of the some areas of the land are often a few degree higher than the surrounding areas. Such areas are called as heat islands. Heat islands are mostly formed in cities.
One of the reason is that the buildings and pavements absorb a significant amount of heat that warm the cities. Another reason is that the less vegetation in the urban areas. Various other factors contributing to the heat islands are: urbanization, vehicle emission, air conditioners etc.
Disaster Management
Module-4-Disaster Management
78. Disaster
Disaster is a series of disruptions which affect the functioning of a community and it causes widespread human, material and environmental losses.
Disasters may be caused by natural or man made hazards.
Natural hazards
- Earth quake
- Volcanic eruptions
- Draught
- Forest fire
- T-sunami
- Epidemics
- Cyclone
- Flood
- Volcanic eruptions
- Draught
- Forest fire
- T-sunami
- Epidemics
- Cyclone
- Flood
Man made Hazards
- Transport accidents(train, road, ship and flight)
- Building collaps
- War
- Mass shooting
- Nuclear explosions
79. Hazard
- Transport accidents(train, road, ship and flight)
- Building collaps
- War
- Mass shooting
- Nuclear explosions
Hazards are the events that has potential to cause loss of life, injury, socio-economic disruptions and environmental degradation. Hazards may be natural or man made.
Natural hazards
- Earth quake
- Volcanic eruptions
- Flood
- Draught
- Forest fire
- T-sunami
- Epidemics
- Cyclone
- Earth quake
- Volcanic eruptions
- Flood
- Draught
- Forest fire
- T-sunami
- Epidemics
- Cyclone
Man made Hazards
- Transport accidents(train, road, ship and flight)
- Building collapse
- War
- Mass shooting
- Nuclear explosions
- Transport accidents(train, road, ship and flight)
- Building collapse
- War
- Mass shooting
- Nuclear explosions
80. Difference between hazard and Disaster
- Disaster is the term used to represent the disruptions or losses occurring for a short period of time in a community. These losses may be human, material, economic or environmental
- Hazards are the man made events or natural phenomena which have the potential to bring disaster in community.
- A Hazard may not always cause disaster because it depend upon the vulnerability of that community also.
For example, for a community living in an area have safer building structures, earthquake may not be disastrous for them but depend upon its magnitude.
- All hazards may not cause disasters. For example, a hurricane far out to sea cannot harm the people.
81. Vulnerability, risk and capacity
Vulnerability
It is the measure of weakness of a community or group of people to cope with, resist or recover from the impacts of hazards.
A more vulnerable community is more susceptible to disasters. After effects of the hazards depend upon the vulnerability of the affected community.
Risk
Risk is the potential of loss, damage or destruction of an asset as result of hazard. Risk is the measure derived from the product of hazard and vulnerability.
Risk = hazard x vulnerability
i.e. If a community is more vulnerable to a hazard event, that community is at more risk.
Capacity
It is the strategies within the community to make them less vulnerable to hazards.
82. Disaster and development
Disaster and Development are closely linked. Disaster can both destroy developmental initiatives and create development opportunities.
Disasters set back development programs destroying years of developmental initiatives.
The current approach of development programs are being designed to include disaster recovery programs and conform to sustainable development ideas.
Solid Waste Management
Solid Waste Management
74. Solid waste- Cause and effects
The origin of the solid waste may be from domestic places, industries, commercial sites, construction sites, and institutions like hospitals, hotels and apartments. The domestic wastes are maybe mostly of organic wastes which is easily degradable and environmental friendly.
E ffects of solid waste
Solid wastes cause environmental pollution in a number of ways and its adverse effects.
i) The garbage disposal area is the breeding places for flies, mosquitoes, rats, and animals like pigs and dogs. These all transmit diseases to the human being. Mosquitoes bring malaria and dengue fever. Rats transmit plague. Mosquitos biting pigs cause to transmit diseases like brain fever from pigs to human beings.
ii) Contaminate the underground water and other water bodies like well, pond, lake and river.
iii) The untreated solid wastes emit greenhouse gases like methane, carbon dioxide which are the major contributors for global warming.
iv) Burning of garbage will also produce other pollutants like toxic fumes and particulate matters.
v) Unfair smell or bad odour is one of the major issues which make the life of the surrounding people miserable
iii) The untreated solid wastes emit greenhouse gases like methane, carbon dioxide which are the major contributors for global warming.
iv) Burning of garbage will also produce other pollutants like toxic fumes and particulate matters.
v) Unfair smell or bad odour is one of the major issues which make the life of the surrounding people miserable
75. Solid waste management
The meaning of solid waste management is the supervised handling of the solid waste materials from the generated source through the recovery process and disposal. The following data will give the importance of the requirement of a proper Solid Waste Management. i.e. The totally generated waste in India is 62 million tons. In that plastic waste is 5.6 million tons, biomedical waste is for n 1.7 million tons, hazard waste is about 7.9 million tons and the e-waste is 15 lakhs tons.
The solid waste management includes mainly four steps.
Storage, Collection, Transportation and Disposal.
Storage
First of all wastes are stored in waste bins, drums or boxes which is placed in many different places in the cities or housing areas.
Collection
Stored wastes are collected at door to door by the rag pickers who generally collect usable materials.
Transportation
These collected wastes are transported to the disposal or treatment site by using specially equipped trucks and many workers with the special masks, gloves and other dress materials for health safety.
Disposal
It is the fundamental function of solid waste management. It refers to placing the solid waste in its ultimate resting places and then further treatment processes.
The different methods adopted for solid waste disposal and treatment are - open dumping, landfilling, sanitary landfilling, ocean dumping, incineration, pyrolysis, composting and vermicomposting.
76. Solid waste treatment methods
The different methods adopted for solid waste disposal and treatment are - open dumping, landfilling, sanitary landfilling, ocean dumping, incineration, pyrolysis, composting and vermicomposting.
Open dumping
It is the method of dumping the waste in open areas, which is far away from the cities or unmanned areas. This method is not possible in populated areas and it is mostly used in the deserts in the Gulf countries.
It is the method of dumping the waste in open areas, which is far away from the cities or unmanned areas. This method is not possible in populated areas and it is mostly used in the deserts in the Gulf countries.
Landfilling
The wastes are carried and dumped in low-lying areas.
The wastes are carried and dumped in low-lying areas.
Sanitary land filling
As in open dumping and landfilling the decomposed material percolate down to the underground and contaminate the underground water, the third method called sanitary landfilling is used to solve these issues. In this method, specially made garbage pits are lined with plastic or some other material. Thus isolate the sand from the waste material. After filling a layer of garbage it will be covered with sand and again garbage and it will be continued. It is highly costlier.
Ocean dumping
In this method, the solid waste is packed in a particular way and dumped into the ocean. But it has a disadvantage that it will adversely affect the Marine ecosystem.
Incineration
Incineration means burning of the solid waste in properly constructed furnace. This method is applied when suitable dumping places are not available. In this method first of all the combustible and non-combustible materials are separated. The final products will be ashes and clinkers which can be reused for various purposes.
As in open dumping and landfilling the decomposed material percolate down to the underground and contaminate the underground water, the third method called sanitary landfilling is used to solve these issues. In this method, specially made garbage pits are lined with plastic or some other material. Thus isolate the sand from the waste material. After filling a layer of garbage it will be covered with sand and again garbage and it will be continued. It is highly costlier.
Ocean dumping
In this method, the solid waste is packed in a particular way and dumped into the ocean. But it has a disadvantage that it will adversely affect the Marine ecosystem.Incineration
Incineration means burning of the solid waste in properly constructed furnace. This method is applied when suitable dumping places are not available. In this method first of all the combustible and non-combustible materials are separated. The final products will be ashes and clinkers which can be reused for various purposes.Pyrolysis
As in the incineration process, the burning of waste produces more carbon dioxide and particulate matters which also are a pollutant. So this issue can be solved in this method called pyrolysis. In this method the wastes are heated at 650 degrees Celsius in low oxygen or oxygen free environment. The end products are gas and tar which can be used for either as fuel or it can be used for industrial purposes.
As in the incineration process, the burning of waste produces more carbon dioxide and particulate matters which also are a pollutant. So this issue can be solved in this method called pyrolysis. In this method the wastes are heated at 650 degrees Celsius in low oxygen or oxygen free environment. The end products are gas and tar which can be used for either as fuel or it can be used for industrial purposes.
Composting
In this method waste materials are decomposed into humus and stable, mineral compounds by biological process like using fungi and bacteria. This method is considered as best suited for Indian conditions, especially for small and medium-sized towns.
In this method waste materials are decomposed into humus and stable, mineral compounds by biological process like using fungi and bacteria. This method is considered as best suited for Indian conditions, especially for small and medium-sized towns.
Vermicomposting
In this method, earth worms are added in the compost to make it richer in nutrients.
In this method, earth worms are added in the compost to make it richer in nutrients.
77. EIA
EIA is the legal framework, accepted worldwide as part of environmental protection acts which regulate the activities which access, utilize and pollute the natural resources. As per the norms of EIA, every developmental project has been required to go through the EIA process for obtaining prior environmental clearance or permit ever since. India notified its first EIA norms in 1994. Recently Indian government notified a modification in the EIA norms of 2006
Nuclear Pollution
Module 3 - POLLUTION
70. Radio active/nuclear pollution
Radio active pollution occurs when there is presence of radio active materials in the atmosphere. The radio active materials like Uranium, thorium etc. emit hazardous ionizing radiations of beta or alpha particles, gamma rays or neuron into the environment.
71. Causes of radio active pollution
1. Nuclear accidents from nuclear power plants. Examples -
Chernobyl, Fukushima, Thee mile Iceland
2. Use of nuclear weapons for mass destruction as in Hiroshima and Nagasaki.
3. Use of radio isotopes for detectors and other industrial activities. Radio isotopes are used in smoke detectors, watches, clocks, non stick cookware, cosmetics, sterilization etc.
4. Mining radio active mineral ores like radium and uranium cause pollution.
5. Tests using radiation therapy like X-ray.
72. Effects of radio active pollution
1. Genetic mutation
2. Diseases like Cancer, Leukaemia, aging, premature death, cardio vascular complications etc.
3. Cells destruction
4. Reduce soil fertility
5. Burns leading to skin cancer
73. Control measures- nuclear pollution
1. Radio active materials should not be disposed in the same way as other materials. It should be stored in heavy and thick concrete container. Another option is to dilute the radiation.
2. Labelling: It is necessary for any material with radio active contents to be labelled and the necessary precaution advised on the content of the label.
3. Banning of nuclear tests.
4. Use other alternate energy resources like solar, wind, tide, hydel energy for energy production.
5. Recycle and reuse the radio active materials like fuel in another reactor.
Oil and Thermal Pollution
Module 3 - POLLUTION
Marine Oil Pollution
Oil exploration and oil transportation causes the ocean with spillage of large quantity of oil. Oil tanker accidents, international discharge of oil into sea water are also the reason of marine oil pollution.
66. Causes of marine oil pollution
Oil exploration and oil transportation causes the ocean with spillage of large quantity of oil. Oil tanker accidents, international discharge of oil into sea water are also the reason of marine oil pollution. The various causes of marine oil pollution are:
1. Oil tankers (ship) are one of the major source of oil spills.
2. Oil explorations either onshore or offshore causes release of oil into the ocean from oil wells.
3. Minor oil spills from the oil pipe lines occur very frequently.
4. International discharge of oil into sea water is a recent phenomenon which has occurred during the gulf war.
67. Control measures of oil pollution
2. Oil explorations either onshore or offshore causes release of oil into the ocean from oil wells.
3. Minor oil spills from the oil pipe lines occur very frequently.
4. International discharge of oil into sea water is a recent phenomenon which has occurred during the gulf war.
1. Contingency planning is required for the abatements of oil spill persistence testing using local marine organizations.
2. The cleaning o the oil spills can be carried out by the placement of specially designed floating blooms.
3. Sinking agents such as chalk, dispersants etc. convert oil into a more easily handled visco-elastic substance.
4. Adopt biodegradation processes to break down the oil.
5. Enforcement of laws to control marine pollution on coastal areas.
68. What is thermal pollution?
The discharge of warm water into the water bodies are usually called as thermal pollution. It occurs when industries like thermal power plants use the water from the water bodies for cooing turbines and return the waste hot water into it.
When the temperature of the water rises, it reduce the solubility of oxygen and change the ecological balance of the river.
Thermal pollution can be controlled by passing the heated water through a cooling pond or cooling tower after it leave the machine. The heat is dissipated into the air and then the water can be discharged into the water bodies.
69. Causes/sources of thermal pollution
1. Nuclear Power plants
Nuclear power plants, experiments, explosions etc. release a large amount of heat nearby water streams.
2. Coal fired power plants
Thermal power plants are a major source of thermal pollution.
3. Industrial effluents
Industries like paper, textile, sugar etc. release heat into the water.
4. Domestic sewage
The sewage water discharged into the water bodies are higher in temperature than the receiving water.
Noise Pollution
Module 3 - POLLUTION
63. Causes/sources of noise pollution
Noise is the undesirable or unwanted sound. It is not harmful as the contamination of air and water. But it is a pollution problem that affect the human being.
Sources of Noise pollution
- Factories
- Vehicles
- Loud speakers
- Music systems
- Fire crackers
- Vehicles
- Loud speakers
- Music systems
- Fire crackers
64. Effects of noise pollution
- Physical damages to the ear and temporary or permanent loss of hearing.
- In addition to the hearing loss, excessive sound for a long period of time cause harmful effects on circulatory system by rising blood pressure and altering pulse rate.
- Noise also cause emotional or psychological effects such as irritation, anxiety, stress, lack of concentration and mental fatigue.
- Underwater species like whales are seriously affected by noise rom the marine transport.
65. Control devices for noise pollution
There are 4 fundamental ways by which noise can be controlled.
1. Reduce noise at the source
2. Block path of the noise
3. Increase the path length
4. Protect the recipient
1. Reduce the noise at the source
Noise can be reduced by effectively muffing the vehicles and machines with sound absorbing materials.
In industries noise reduction can be done by
i) Using rigid sealed enclosures around the machine lined with sound absorbing materials
ii) Isolate the machines and their enclosures from the floor using special shock absorbing mounts and pads.
iii) Use flexible couplings in joints.
vi) Regular and thorough maintenance of machineries and vehicles.
2. Block the path of the noise
Isolate the source of noise from the recipients by blocking the path by sound proof material.
3. Increase the path length
i) Locate noisy compressors, generators and other equipment away from work sites.
ii) Establish schools and hospitals away from traffic areas, airports and industries.
4. Protect the recipient
The use of earmuffs can protect the individuals from excessive noise level
Water Pollution
Module 3 - POLLUTION
57. Water Pollution
The various causes or sources of water pollution are:
Contamination of waterbodies like ocean, river, lake, pond and underground water with undesirable substances are called water pollution
1. Oxygen demanding wastes
2. Pathogens
3. Nutrients
4. Salt
5. Thermal pollution
6. Heavy metals
7. Pesticides and fertilizers
58. Causes of water pollution
The various causes of water pollution are:
1. Oxygen demanding wastes
Municipal waste water and industrial effluents reduce the dissolved oxygen in water. When the amount of dissolved oxygen reduces and the following effects are occurred:
a) fishes and other aquatic life are threatened and in the extreme cases killed.
b) Undesirable odour, taste and colour make the water useless.
a) fishes and other aquatic life are threatened and in the extreme cases killed.
b) Undesirable odour, taste and colour make the water useless.
2. Pathogens
They are disease producing organisms that grow and multiply within the host. E.g. Bacteria, Fungi
3. Nutrients
The nutrients like nitrogen, phosphorous, potassium etc. are considered as pollutants when their concentration are large to allow excess growth of aquatic plants and causes eutrophication effect.
4. Salt
Salt concentration in water reduces its acceptability for domestic,industrial and agricultural purposes.
5. Heavy metals
Heavy metals like mercury, cadmium, lead etc. are considered as pollutants, as these metals adversely affect the human health.
6. Other pollutants
The various other materials that causes water pollution are, plastic,chemicals, marine oil, radio active wastes etc.
59. Sources of water pollution
1. Point sources like industries and municipal sewage treatment plants.
2. Diffused sources like agricultural land, mine, construction sites etc.
60. Effects of water pollution
- Oxygen demanding wastes like municipal waste water reduces the acceptability of water for domestic use and aquatic lie is threatened.
- Excess quantity of nutrients like nitrogen, phosphorous etc. causes eutrophication effect thereby make the water bodies dead.
- Heavy metals like mercury, cadmium, lead etc. cause diseases like nervous and kidney failure in human being.
- Excess salt in water makes it not suitable for domestic use and irrigation purposes.
- Disease causing pathogens like viruses spread viral diseases.
- Hot water discharge from the power plants to the nearby waterbodies adversely effect the aquatic life.
61. Control measures of water pollution
1. Enforcement of laws to prevent water pollution.
2. Citizen should be aware and strictly follow all the laws regarding water pollution.
3. Industries should behave more responsibly.
- Waste should be disposed properly.
- Make changes in the processes to avoid water pollution.
- Effluents must be treated and cooled before running out to waterbodies.
4. Clean drainage and sewage canals regularly.
5. Develop technology to keep the drainages away from water resources.
6. To reduce the chemical fertilizers and pesticides, adopt organic farming.
7. Treat the sewage water from plants before it is disposed into waterbodies.
62. Water treatment methods
The following steps are involved in the water treatment process,
1. Screening
Screening is done to remove relatively large floating and suspended debris.
2. Coagulation
Chemicals like iron salts, lime and alum are added to neutralize the negative charges on the particles, so that they can stick together to form large particles and can be easily removed.
3. Flocculation
Coagulated water flows into a tank with paddle type mixer in which small particles stick together to form large particles called flocs.
4. Sedimentation
In sedimentation, water flow is slowed enough so that the flocs will settle by gravity.
5. Filtration
Small impurities are removed by percolating the water downward through a layer or a bed of porous granular material such as sand.
6. Disinfection
Filtered water is disinfected by adding chlorine and bleaching powder.
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99 essential questions in Environmental Science and Disaster Management
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